Scanning techniques for probing and measuring anatomical cavities

ABSTRACT

Methods and apparatus, including computer program products, are provided for scanning an anatomical cavity. The method may include: selecting a scan path for obtaining data from sample areas inside the anatomical cavity, exciting a fluorescent material in an inflatable membrane that conforms to the anatomical cavity, measuring emitted light from the fluorescent material for each sample area, and characterizing the anatomical cavity. Characterizing may be based on at least one of a location or an intensity measurement for each sample area. The method may be executed using a scanning system that includes the inflatable membrane.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 61/790,491, titled “Apparatus and Methods for Probing andMeasuring Anatomical Cavities,” filed Mar. 15, 2013, the disclosure ofwhich is hereby incorporated by reference herein.

FIELD

The subject matter described herein relates to probing and measuringcavities, particularly anatomical cavities such as a human ear canal.

BACKGROUND

Devices can be created to fit into anatomical cavities, such as thehuman ear canal. When creating such devices, having a comfortable andsnug fit between a device and the cavity into which it is placed canincrease the likelihood that a user will wear the device, as well asenhance the performance of the device.

Traditional methods of probing and measuring sensitive cavities, such asanatomical cavities, include creating impressions of the cavity.Creating or taking an impression includes injecting a material into thecavity. The material is allowed to harden and conform to the shape ofthe cavity, and then the material is extracted from the cavity. Animpression created this way can cause complications or pain when theimpression material is injected into the cavity, when the material ishardening, or when the impression is extracted. Such actions can exertpressure on the walls of the cavity in a painful or damaging way.

SUMMARY

Methods, systems, and apparatus, including computer program products,are provided for scanning techniques for probing and measuringanatomical cavities. For some example implementations, there is provideda method for scanning an anatomical cavity. The method may includeselecting a scan path for obtaining data from sample areas in ananatomical cavity, exciting a fluorescent material in an inflatablemembrane of the scanning system, measuring emitted light from thefluorescent material for each sample area, and characterizing theanatomical. The selecting, exciting, and measuring, may be done using ascanning system. Each sample area of a scan path may be situated in alocation in the anatomical cavity being scanned, and the inflatablemembrane may conform to the anatomical cavity.

In some implementations, the above-noted aspects may further includeadditional features described herein including one or more of thefollowing. The scan path may include at least one of a hub and spokepattern or a spiral pattern. In such implementations, the hub and spokepattern may include a hub location and two or more spokes, the hublocation being the first sample area in the scan path and the two ormore spokes each including at least two areas located along a line.Further, in such implementations, the hub location may be one of the atleast two sample areas for each spoke. The spiral pattern can include ahome location that is the first sample area in the scan path and atleast one consecutive data point, in some implementations of the method.In such implementations, the at least one consecutive data point may bea sample area that includes an area of the anatomical cavity that isincluded by the home location or one or more of the at least oneconsecutive data points. In some implementations, the methods mayinclude supporting features external to the anatomical cavity. Themethods may further include scanning from an outside portion of theanatomical cavity to an inside portion of the anatomical cavity. In someimplementations, the anatomical cavity may include an ear canal. Thecharacterizing of the anatomical cavity, in some implementations of themethod, may be based on at least one of a location of each sample area,an intensity measurement for each sample area, and a ratio ofintensities measured for each sample area.

In a related aspect, provided herein are apparatus for scanning ananatomical cavity that include a three-dimensional (3D) scanner and aprocessor. The 3D scanner includes a light source, a detectingcomponent, a probe element, and an inflatable membrane. The light sourcemay generate light for scanning and for identifying locations within theanatomical cavity. The detecting component may receive emitted lightfrom within the anatomical cavity, and the detecting component maygenerate data from the received light. The probe element may guide thelight generated by the light source, and the inflatable membrane maysurround the probe element. The inflatable membrane may also beconfigured to inflate with a medium until the inflatable membraneconforms to the volume of the anatomical cavity.

In some implementations, the above-noted aspects relating to anapparatus for scanning an anatomical cavity may further includeadditional features described herein including one or more of thefollowing. In some implementations, the scan path may be generated by atleast one of: the three-dimensional scanner, at least one processor,and/or a scanner system. Additionally, or alternately, the scan path maybe based upon input from a user. The scan path may include at least oneof a hub and spoke pattern or a spiral pattern in some implementations.In such implementations, the scan path can include a hub and spokepattern in which a user specifies a hub location for the hub and spokepattern. The user may further specify the number of spokes in the huband spoke pattern. In some implementations, the processor of theapparatus may select the hub and spoke scan path based up the userspecified hub location. The scan path can include a spiral pattern, insome implementations, and a user may specify a home location for thespiral pattern. The processor of the apparatus may select the spiralscan path based upon the user specified home location, in suchimplementations.

The above-noted aspects and features may be implemented in systems,apparatus, methods, and/or articles depending on the desiredconfiguration. The details of one or more variations of the subjectmatter described herein are set forth in the accompanying drawings andthe description below. Features and advantages of the subject matterdescribed herein will be apparent from the description and drawings, andfrom the claims.

DESCRIPTION OF DRAWINGS

In the drawings,

FIGS. 1A depicts an example of a system including a three-dimensional(3D) scanner having an inflatable membrane;

FIG. 1B depicts an example 3D rendering of a cavity formed based onscanner data collected by the 3D scanner of FIG. 1A;

FIGS. 1C-D depict examples of a system including a 3D scanner having aninflatable membrane;

FIG. 1E shows a block diagram of a tip portion of the 3D scanner ofFIGS. 1A, C, and D;

FIG. 1F depicts an example implementation of portions of the 3D scanner;

FIG. 2 depicts a scan path that includes a hub and spokes; and

FIG. 3 depicts a scan path that includes a spiral.

Like labels are used to refer to same or similar items in the drawings.

DETAILED DESCRIPTION

Injection of materials into sensitive cavities, such as anatomicalcavities, can, as noted, cause pain and/or damage to the cavity.Alternative methods for probing and measuring such cavities may includescanning techniques that utilize light. Described herein are methods,apparatus, and systems for scanning techniques for probing and measuringanatomical cavities, including the human ear canal.

FIG. 1A depicts a system 100 including an inflatable membrane 110, inaccordance with some example implementations. The system 100 maygenerate three-dimensional (3D) scans of a cavity, such as an earcavity.

System 100 may include a 3D scanner 195 including inflatable membrane110 and a processor 190, such as computer. The processor 190 may processscanner data generated by 3D scanner 195 during a scan of the cavity.The processor 190 may form an output, such as a 3D impression of thescanned cavity. FIG. 1B depicts an example of a 3D surface formed byprocessor 190 based on scan data provided by 3D scanner 195. The 3Dsurface may model the cavity being scanned, such as an ear cavity, andthis 3D surface may be provided to a manufacturer, 3D printer, and thelike to form an object. In the case of the ear, the object may be anearpiece.

FIG. 1C depicts a portion of 3D scanner 195 after being inserted into anear cavity 182 and after a medium 120 is used to expand the interior ofthe inflatable membrane 110, so that the inflatable membrane 110conforms to the ear cavity 182 (or portion of the ear cavity and/or anyother cavity or surface being scanned). For example, the medium 120 maybe inserted into the membrane 110, so that membrane 110 conforms to thecavity being scanned. At this point, scanner element 105 may scan theinterior surface of the inflatable membrane 110 which when inflated withthe medium 120 conforms to the ear cavity 182. The scanner element 105may move within the membrane 110 to scan the interior surface ofmembrane 110. In this way, scanner element 105 may scan the interiorsurface of the membrane 110 and thus ear cavity 182. The scanner element105 may generate a 2D image of the inflatable membrane approximating thea snap shot of the anatomical cavity. Each pixel of the 2D image is thenassociated with distance information obtained during a scan, that is thedistance from the scanner element 105 to the scanned portion of themembrane. The combination of the 2D image and distance information foreach pixel of the 2D image corresponds to 3D data (for example, a 3Dsurface representative of the scanned cavity). In some implementations,the distance information determined from scanning data can correlate togroups of pixels, instead of a single pixel, on the 2D image.

Medium 120 may be a liquid, a gas, a gel, a hydrogel, and/or anycombination of the four. The medium 120 may include additives dissolvedinto, or suspended in, the medium 120 to provide properties, such asselective absorption where one or more wavelengths of light are absorbedmore than one or more other wavelengths. To illustrate, medium 120 mayinclude a colored dye, suspension, a luminescent substance, and/or afluorescent substance (and/or any other material having selectivewavelength properties). Moreover, the selective wavelength propertiesmay, as described further below, allow 3D scanner and/or processor 190to determine the shape of, distance to, and/or other properties of thescanned interior surface of membrane 110.

The inflatable membrane 110 may be implemented as any viscoelastic,elastic, plastic, and/or any other material that may be inflated toconform to the cavity, when the membrane 110 is inserted and inflatedwith medium 120. When the cavity corresponds to an ear canal, membrane110 may have an inflated 3D shape and size that is substantially adaptedto the ear cavity, although the membrane 110 may be used with othercavities and forms as well including a stomach, an esophagus, a bladder,and so forth. The membrane 110 may also include, or be coated with, amaterial to make the membrane fluoresce in the presence of white light,light of a particular wavelength, or a range of wavelengths, as furtherdescribed below. In some implementations, the inflatable membrane mayhave a balloon-like shape with an opening, an interior surface, and anexterior surface. In some implementations, scanning the interiormembrane 110, rather than the ear cavity directly, may reduce (if noteliminate) the interference caused by artifacts, such as ear hair, wax,and the like, and may thus improve the quality of the cavity scan.

FIG. 1D depicts scanner element 105 after the scanner element has movedtowards the opening of the cavity as part of the cavity scanningprocess. While scanning, scanner element 105 may scan one or moreportions of the interior surface of the membrane 110, and element 105may move within the membrane (and ear cavity 182) to image some (if notall) of the inner membrane 110/cavity 182. The scanner data collected by3D scanner 195 may then be provided to one or more processors, such ascomputer 190 and/or a cradle-like device including an intermediaryprocessor, to form a 3D surface or impression representative of thecavity as depicted at FIG. 1B, although some (if not all) of theprocessing may be performed by a processor contained in the 3D scanner195 as well.

FIG. 1E shows a block diagram of the tip portion of 3D scanner 195 and,in particular, scanner element 105, inflatable membrane 110, and medium120. The 3D scanner 195 and/or the scanner element 105 may include atleast one light source, such as a light emitting diode, for emittinglight 115 into the inflatable membrane 110, including medium 120. Thescanner element 105 may also collect and/or detect light 125 and 130that is emitted from fluorescent material in, or on, the inflatablemembrane 110. The light 115 emanating from scanner element 105 maycomprise light used to excite the fluorescent material in, or on, theinflatable membrane 110. Further, light from the fluorescent materialin, or on, the inflatable membrane 110 may be referred to as“fluoresced” light, i.e., light resulting from the interaction of thefluorescent material with the light from scanner element 105.

The inflatable membrane 110 may include a fluorescent material, such asone or more fluorescent dyes, pigments, or other coloring agents. Thefluorescent material can be homogenously dispersed within the inflatablemembrane 110, although the fluorescent material may be applied in otherways as well (for example, the fluorescent material may be pad printedonto the surface of the inflatable membrane). The fluorescent materialmay be selected so that the fluorescent material is excited by one ormore wavelengths of light 115 emitted by the scanner element 105. Oncethe fluorescent material is excited by light 115, the fluorescentmaterial may emit light at two or more wavelengths λ₁, λ₂, or a range ofwavelengths. For example, wavelength λ₁may represent a range ofwavelengths associated generally with red, although wavelength λ₁ may beassociated with other parts of the spectrum as well.

As the two or more wavelengths 125 transmit back through the medium 120,absorbing medium 120 may absorb one or more of the wavelengths of lightλ₁, λ₂ to a greater degree than one or more other wavelengths of thelight. The medium 120 used in the system 100 may also be selected tooptimally and preferentially absorb one or more of the wavelengths or arange of wavelengths of light from the fluorescent material of theinflatable membrane. By selecting a medium that complements thefluorescent material, the scan data collected by the 3D scanner may bemore accurate.

When the tip portion 100 of 3D scanner 195 is inserted into ear cavity182, 3D scanner 195 may pump (or insert in other ways) medium 120 intoinflatable membrane 110 until the inflatable membrane 110 conforms tothe surface of the cavity 182. Once the inflatable membrane 110 is fullyinflated, 3D scanner and/or scanner element 105 may include a lightemitting diode that generates light 115. Light 115 may travel from thescanner element 105, through medium 120, and excite the fluorescentmaterial on, or in, a portion of the inflatable membrane 110. The lightemitted from the fluorescent material on, or in, the inflatable membrane110 may include at least two wavelengths of light. One of thewavelengths of light, or some ranges of wavelengths of light, emitted bythe fluorescent material may be selectively absorbed by the medium 120.The light λ₁, λ₂, or ranges of light, may then be received by thescanner element 105, and the ratio of the intensities of light λ₁, λ₂ orthe ratio of the integral area of light found under specific ranges maybe measured and recorded by 3D scanner 195 and/or processor 190 todetermine a distance from the scanner element 105 to correspondingsurface of the membrane 110. The scanner element 105 may move throughoutinterior of membrane 110 to scan various portions of the surface of themembrane 110 and receive the fluoresced wavelength of light 125, 130 inorder to collect data that can be used by the 3D scanner 195 and/orprocessor 190 to form 3D surface representative of the cavity.Alternatively, or additionally, the scanner element 105 may includeoptical, electronic, or mechanical means of focusing and directing thelight used to excite the fluorescent material. Although the scannerelement 105 may include one or more components, such as one or morelight emitting diodes, optics, lenses, detectors/CCDs/CMOS sensors, andthe like, one or more of these components may be located in otherportions of the 3D scanner (for example, a fiber may carry light 115 toscanner element 105).

FIG. 1F depicts an example implementation of the 3D scanner 195front-end, in accordance with some example implementations. The 3Dscanner 195 may have a shroud 196 that houses an illumination component197 and a sensing component 198. A cable 194 can connect the 3D scannerto the processor 190. Connected to the shroud 196 of the 3D scanner isthe scanner element 105, or probe, which includes lenses 106 to focuslight. The illumination component 197 produces light that excites thefluorescent material in the inflatable membrane, as well as light thatmay allow for general viewing of the cavity being scanned and the areaaround the cavity, such as when locating an area of interest. The lightgenerated by the illumination component 197 for general viewing may bewhite light generated by one or more light source, such as one or morelight emitting diodes. The light generated by the illuminationcomponents 197 for excitation of the fluorescent material in theinflatable membrane may be blue light generated by one or more lightsource, such as one or more light emitting diodes. The sensing component198 may include one or more of a mirror, a beam-splitter, a filter, andmultiple detectors. Each detector sends data to the processor 190through the cable 194. The data from the one or more detector may becombined, multiplexed, or otherwise processed before it is sent throughthe cable 194. The processor 190 may send commands, such asillumination, scanning, or focusing instructions, to the front-end ofthe 3D scanner through the cable 194. The configuration the componentsof the front-end of the 3D scanner shown in FIG. 1F is a representativeconfiguration. The 3D scanner may have an illumination component 197,sensing component 198, probe 105, and processor 190 in otherconfigurations suitable for scanning a cavity, such as an anatomicalcavity.

Referring again to FIG. 1D, to determine distance from the scannerelement 105 and a corresponding surface of the interior of membrane 110,the ratio of the intensity of two or more wavelengths or ranges ofwavelengths may be used. Specifically, the intensity of the lightemitted by the fluorescent material may be measured and recorded for atleast two wavelengths, λ₁, λ₂, or ranges of wavelengths, one of which isthe wavelength, or wavelength range, that is preferentially absorbed bythe medium 120. The ratio of the intensity of two or more wavelengths orranges of wavelengths, at least one of which is preferentially absorbedby the medium 120, allows the 3D scanner 195 and/or processor 190 tocalculate the distance between the fluorescent material of theinflatable membrane 110 and the distal tip of the scanner element 105that receives the light 125, 130 from the fluorescent material. Thelight 115 from the scanner element 105 may scan the inner surface of themembrane 110 by illuminating points or areas on the inflatable membrane110 in a sequential manner, so that an array of ratios of intensities ofthe wavelengths, and thus distances, corresponding to points on theinflatable membrane 110 can be created. As noted above, the scannerelement 105 may move within the membrane 110 to allow illuminatingportions along some, if not all, of the entire inner surface of themembrane 110.

The 3D scanner 195 may include a spectrometer to measure intensities forthe two or more wavelengths, or ranges of wavelengths, of light from thefluorescent material. The wavelengths of light that can be comparedinclude red light (such as light with wavelength ranging from about 620to about 750 nanometers (nm)) and green light (such as light withwavelength ranging from about 495 to about 570 nm). Additionally, oralternatively, the intensity of other wavelengths of light can bemeasured and compared, such as any combination of violet light(approximately 380 to 450 nm), blue light (approximately 450 to 495 nm),green light (approximately 495 to 570 nm), yellow light (approximately570 to 590 nm), orange light (approximately 590 to 620 nm), and redlight (620-750 nm). The spectrometer can include one or more detectors,such as CCD (charge coupled device) or CMOS (complementary metal-oxidesemiconductor) detectors, to measure the intensity of light, as well asimplements to select the wavelengths to be measured, such as one or moregrating, beam splitter, or filter.

The 3D scanner 195 may also measure the intensity of one or morewavelengths or ranges of wavelengths of light from fluorescent materialembedded in, or on, the inflatable membrane as a function of the degreeof inflation of the membrane. That is to say, the inflatable membranecan be inflated to multiple levels of inflation while inside of ananatomical cavity, and measurements of the intensity of one or morewavelengths or ranges of wavelengths of light emitted from fluorescentmaterial embedded in or on the inflatable membrane can be recorded andused to determine at least a 3D image or a surface topography of theanatomical cavity corresponding to this one or more levels of inflation.In the case of the human ear, particularly the aural canal, the size ofthe canal and compliance of the tissue in the canal can be determined,and the location of anatomical features, such as the bone-cartilagejunction, can be found. Knowledge of the shape, compliance, and locationof anatomical features can be used to create a device that providesbetter sound transmission, more comfort to a device user, or for thedevelopment of device materials. In some example implementations, themembrane 110 may be dynamically inflated to different pressures toenable the 3D scanner 195 to better scan certain anatomical features,such as the bone-cartilage junction and the like. This may be aided byasking the patient to move her anatomical features, for example bychewing, during the scan, and by observing changes in measurements as afunction of this anatomical feature displacement.

The 3D scanner 195 may, as noted above, excite points or portions of theinflatable membrane in a sequential manner to obtain data that allowsfor the determination of the shape and mechanical properties, such ascompliance, of the anatomical cavity surrounding the inflatablemembrane. The scan method and path, or sequence of points selected bythe user or the system, can be chosen to improve accuracy, speed, orrepeatability of the measurements made by the system. For example, 3Dscanner 195 including the scanning elements 105 may be configured toallow scanning in a variety of methods and patterns to obtain asaccurate a rendering of the anatomical cavity as possible. Such methodsand scan patterns may include a hub-and-spoke pattern, a spiral pattern,and/or any other method or pattern.

In the case of scanner element 105, fluorescent imaging through medium120 may, as noted, selectively absorb one wavelength or range ofwavelengths of light over another, and this selective absorption may beused to determine depth from scanner element 105 to the fluorescentmembrane 110. This depth measurement may, as noted, be based on a ratioof the absorbed-to-transmitted wavelengths or ranges of wavelengths oflight. Moreover, a processor may correlate the depth measurement to thecorresponding scan data/images. For example, a portion of the 2D scannerimage of the fluorescent membrane 110 may be correlated to a depthmeasurement determined from the ratio of the absorbed-to-transmittedwavelengths of light. In this way, the 2D scanner data/image isprocessed into a 3D image or surface.

The 3D scanner 195 including the scanner element 105 may be configuredto allow scanning in a variety of methods and patterns to obtain asaccurate a rendering of the anatomical cavity as possible. Such methodsand scan patterns include a hub-and-spoke pattern, a spiral pattern,and/or any other method or pattern that provides cavity scanning and/orprovides a reduction in scanning errors. Moreover, these scan patternsmay be used alone or in combination with other patterns. In someinstances, errors in the scan data collected can arise from contact ofthe scanner element 105 with the inflatable membrane 110 or ear cavity182. Methods of scanning which avoid such contact may provide fewer dataerrors, as well as less pain for the patient or person being scanned.

Scan patterns in which the areas sampled, that is to say the illuminatedspots on the inflatable membrane, overlap can also improve the accuracyof the scan data. Knowing that two data points correspond to twophysical locations of interest which overlap in area to a certain degreecan enable the scanning system's processor 190 to determine the accuracyof the data. In some instances when data corresponds to physicallocations that overlap, algorithms may be applied to address noise andother perceived abnormalities in the data. The simplest example of thiswould be a scan pattern that follows a linear, grid-like pattern, inwhich increments in the grid advances a known distance which is lessthan a distance in one of the directions of the sample area. Forexample, if the scan has a sample area of 1 square cm, the scan patternwould advance 0.75 cm in one direction before taking the next datapoint. Eventually the scan would cover an area using a grid ofoverlapping squares and the 3D scanner 195 would have collected data forthat area. The scan patterns described herein may, in someimplementations, improve on such scan patterns by incorporating otherinformation, such as reference points, to augment or supplant the needfor data point overlap.

The scanning methods and scan patterns described below may beimplemented through decisions and action of a user of the scanningsystem, a patient or person being scanned, and/or of a care-giver, suchas a physician, and the like. The scanning methods and scan patterns maybe implemented through the execution of algorithms or protocols basedupon preliminary or prior data, based upon user input, or based uponboth preliminary or prior data and user input. Scan patterns may beexecuted by physical manipulation or motion of scanner element or byfocusing and motion of the light used to excite the fluorescentmaterial. Such focusing and motion can be achieved using opticalimplements, such as lenses and mirrors, electrical implements, motorsand actuators, or a combination thereof. Locating points of reference,such a hub or a home location, may be done by a user, by the system,including the 3D scanner 195, or through a combination of user input andsystem actions.

Hub-and-Spoke Pattern

Regarding the hub-and-spoke pattern, the scanner element 105 may bedirected toward a central, or hub, location. The hub location can be thecenter of a region of interest. For example, when the scanner element105 scans the ear cavity 182, the hub location can be the ear canal. Thescan path can begin at the hub location, illuminating the hub locationand collecting data there first, then move outwards in a straight line,illuminating points and gathering data along the line, sequentially. Thestraight line is a spoke portion of the scan path. The number of datapoints along each spoke can vary, but at least two points per line maybe illuminated by the 3D scanner 195. After the first spoke, the scanpath can return to the hub location to take data and then move outwardsin the direction of a second spoke. The scan path can have as manyspokes as needed to gather sufficient data to characterize theanatomical cavity. By returning to the hub location after each spoke isscanned, the system, including the 3D scanner, allows softwarealgorithms to have a point of reference that reduces dead reckoning-typeerrors.

FIG. 2 is a schematic showing an exemplary anatomical cavity 200 and anexemplary scan path, in which the hub 235 of the scan path is the earcanal, and the spokes of the scan path 240, 250 radiate outward from thehub in both a cross-sectional view, as in FIG. 1D, and as viewed end on,from the perspective of the scanner element 105. In the figure, the scanpath starts at the ear canal, or hub location, 235 where it takes data.The scan then extends up the first spoke 240, illuminating at least onepoint along the spoke 242. Following scanning along the first spoke, the3D scanner 195 repositions the light 115 to return to the hub location235, then generates spots of light and collects data up the second spoke250 to at least one point along the spoke 252, to finally return at thehub location 235. In some implementations, data can be collected bothoutwards from the hub location along each spoke as well as inwardstoward the hub location.

The data points, or points of interest, along the scan path providedistance data that allows the 3D scanner 195 to determine the topographyof the ear canal. The data points may not necessarily overlap to anydegree in a hub and spoke scan path, and so returning to the hub beforestarting each line scan along a spoke can help the processor 190 todetermine where each spoke, and in turn each data point, is with respectto the hub. In FIG. 2, two spokes are shown, but in practice multiplespokes, such as tens of spokes, if not hundreds of spokes, may be partof a hub and spoke scan path used by a system imaging an anatomicalcavity. Information about the compliance of the walls of the anatomicalcavity, including the location of anatomical features where tissue typechanges, can also be determined when the system acquires distance dataat various pressures, or degrees of inflation of the membrane, using ahub and spoke scan path.

Spiral Method

A second type of scan path that improve accuracy is one which utilizesthe spiral method. In the spiral method, the 3D scanner can acquire databy sequentially illuminating areas on the inflatable membrane using ascan path that begins at a home location.

The home location can be the center of the field of interest, an easilyidentifiable location within the field of interest, or any locationwithin the field of interest. The 3D scanner begins illuminating pointsand taking data along the scan path at the home location, and then thescanning system acquires data from points along the scan path as thepath spirals outward from the home location. The scan path is made up ofilluminated points that partially overlap with locations from which datawas previously taken. For example, if the sample area has a diameter of1 cm, each data point can overlap a proceeding data point by an amountless than 1 cm, such as by 0.10 cm, 0.25 cm, 0.5 cm, or the like.Additionally, or alternatively, an illuminated point, or data point, canoverlap with more than one proceeding data point by an amount less thanthe diameter of the data point. This means that the 3D scannerincrementally moves the position of the light exciting the fluorescentmaterial of the inflatable membrane by an amount that is smaller thanthe spot size of the light. In some implementations, the 3D scanneroverlaps each illuminated point, or data point, with one or moreproceeding illuminated points in an amount equivalent to 25% or more ofthe area of the data point, such as 30% or more, including 50% or more,or 75% or more.

FIG. 3 depicts a spiral scan path 360 of a field of interest 300 in botha cross-sectional view, as in FIG. 1D, and as viewed end on, from theperspective of the scanner element 105. The home location 355 in thisexemplary scan path schematic can be the calculated center of an earcanal. Points that are illuminated by the 3D scanner 195 with light 115along the scan path 362, 364, 366 can overlap. In this way, the 3Dscanner can use the overlapping scanned data points, in addition to theknown entity that is the home location 355 to yield distance data thatis self-consistent. Having a known entity or point of reference in thescan can increase the fidelity of the final 3D rendering generated, asthe system processor 190 can utilize existing data associated with thepoint of reference to augment the data acquired in the scan by the 3Dscanner.

In FIG. 3, the spiral scan path 360, along which the 3D scannerilluminates points and collects data, progresses counter-clockwise outfrom the home location 355. However it should be appreciated that thespiral scan path 360 can progress out from the home location 355 in aclock-wise direction. Additionally, or optionally, the 3D scanner canfollow a spiral scan path 360 that can be an Archimedean spiral, aFermat's spiral, a hyperbolic spiral, a logarithmic spiral, a spiral ofTheodorus, a lituss, or a spiral of that is a mixture of any of theaforementioned spirals. The scan path followed by the 3D scanner canalso be three-dimensional spiral, approximated by any of an Archimedeanspiral, a Fermat's spiral, a hyperbolic spiral, a logarithmic spiral, aspiral of Theodorus, a lituss, or a spiral of that is a mixture of anyof the aforementioned spirals. In some implementations, the 3D scannercan follow a scan path can be a three-dimensional spiral that is aspherical spiral, such that it has un-equal spacing between eachconsecutive revolution. Alternatively, or additionally, the spiral scanpath followed by the 3D scanner while acquiring data can be athree-dimensional spiral in which the spacing between each consecutiverevolution is equal.

Though discussed in terms of spiral scan paths, it can be appreciatedthat the 3D scanner may be configured to illuminate areas following ascan path that resembles any suitable geometric shape. Suitablegeometric shapes include pentagrams, triangles, squares, pentagons,hexagons, ovals, ellipses, nested patterns of the aforementioned shapes,fractal patterns, or any combination thereof.

Scanning from Outside to Inside

Another method or type of scan path that can reduce inadvertent contactwith the walls of an anatomical cavity during scanning is one where the3D scanner collects data points along a scan path that begins outsidethe cavity and progresses inwards. In this way, because the scanner ismoving forward, the user can visually see if the scanner is about tocollide with a portion of the anatomical cavity and adjust to avoid it.Such avoidance is more difficult when moving backwards. Additionally,the user or system can identify portions of the anatomical cavity thathave already been scanned. Identification can include recognizing knownanatomical features common to most patients or test subjects. Thisidentification can help the 3D scanner follow a scan path during datacollection that avoids the walls of the anatomical cavity. In the caseof a user scanning the ear canal of a patient, the user can avoidcontact between the scanner element or probe and the walls of thepatient's ear canal, thus avoiding pain and discomfort. In systems orinstances where optical manipulation of the light from the scannerelement 105 cannot allow for illumination of all an anatomical cavity,the 3D scanner 195 may require gross movement of the scanning system bya user, such as progressively inserting the scanner element 105 into theanatomical cavity, which in this case is an ear canal 182.

Deformation of External Features

When the scanner element 105 scans the anatomical cavity that is thehuman ear canal, physically deforming the cavity can facilitateinsertion of a probe or scanner element. This deformation typicallyinvolves pulling on the outer portion of the ear and straightens out theear canal. Once the user inserts the scanner element 105 to a suitabledepth, pulling on the ear can cease. The ear canal will return to itsnatural configuration in areas where it does not contact the scannerelement, and then the 3D scanner can collect data along points on a scanpath, such as the hub and spoke or spiral path, to obtain data as thescanner element 105 moves toward the outer portion of the ear.

External Feature Support

Deformation of portions of the body outside an anatomical cavity caninfluence the shape of the cavity that is being scanned. For example,deformation of the outer portion of the ear can alter the configurationof the inner portion of the ear, such as the ear canal. In someimplementations, a system can include supports to prevent deformation ofexternal features, such as the tragus of the ear, during scanning of theinterior of an anatomical cavity. Such implementations can include theuser holding portions of the patient's anatomy in place by hand or withthe help of an apparatus. Supporting apparatus can include apparatusthat are connected to the scanning element or other portion of thesystem, or connections between the apparatus and the rest of the systemcan be absent.

The scanning methods and scan paths described herein can be used by a 3Dscanner to acquire data from multiple points, or sets of points, aloneor in any suitable combination. Though described as being followed orutilized by the 3D scanner, the scanning methods and scan paths can beexecuted by a user or by an apparatus of the system. Such apparatus ofthe system can be a computer controlled apparatus that requires inputfrom the user, such as identification of reference points, including thehub location in a hub and spoke scan path or the home location in aspiral scan path. The apparatus of the system can be a computercontrolled apparatus with detectors and software sufficient to identifyreference points and determine appropriate scan paths.

The subject matter described herein may be embodied in systems,apparatus, methods, and/or articles depending on the desiredconfiguration. For example, the scanning system (or one or morecomponents therein) and/or the processes described herein can beimplemented using one or more of the following: a processor executingprogram code, an application-specific integrated circuit (ASIC), adigital signal processor (DSP), an embedded processor, a fieldprogrammable gate array (FPGA), and/or combinations thereof. Thesevarious implementations may include implementation in one or morecomputer programs that are executable and/or interpretable on aprogrammable system including at least one programmable processor, whichmay be special or general purpose, coupled to receive data andinstructions from, and to transmit data and instructions to, a storagesystem, at least one input device, and at least one output device. Thesecomputer programs (also known as programs, software, softwareapplications, applications, components, program code, or code) includemachine instructions for a programmable processor, and may beimplemented in a high-level procedural and/or object-orientedprogramming language, and/or in assembly/machine language. As usedherein, the phrase “machine-readable medium” refers to any computerprogram product, computer-readable medium, apparatus and/or device(e.g., magnetic discs, optical disks, memory, Programmable Logic Devices(PLDs)) used to provide machine instructions and/or data to aprogrammable processor, including a machine-readable medium thatreceives machine instructions. Similarly, systems are also describedherein that may include a processor and a memory coupled to theprocessor. The memory may include one or more programs that cause theprocessor to perform one or more of the operations described herein.

Although a few variations have been described in detail above, othermodifications or additions are possible. In particular, further featuresand/or variations may be provided in addition to those set forth herein.For example, the implementations described above may be directed tovarious combinations and subcombinations of the disclosed featuresand/or combinations and subcombinations of several further featuresdisclosed above. In addition, the logic flow depicted in theaccompanying figures and/or described herein does not require theparticular order shown, or sequential order, to achieve desirableresults. In various example implementations, the methods (or processes)can be accomplished on mobile station/mobile device side or on theserver side or in any shared way between server and userequipment/mobile device with actions being performed on both sides. Thephrases “based on” and “based on at least” are used interchangeablyherein. Other implementations may be within the scope of the followingclaims.

What is claimed:
 1. A method for scanning an anatomical cavitycomprising: selecting, using a scanning system, a scan path forobtaining data from sample areas in a predetermined pattern, each samplearea situated in a location in the anatomical cavity; exciting, usingthe scanning system, a fluorescent material in an inflatable membrane ofthe scanning system, the inflatable membrane conforming to theanatomical cavity; measuring, using the scanning system, emitted lightfrom the fluorescent material for each sample area; and characterizingthe anatomical cavity.
 2. The method of claim 1, wherein the scan pathcomprises at least one of a hub and spoke pattern or a spiral pattern.3. The method of claim 2, wherein the hub and spoke pattern comprises: ahub location; and two or more spokes, the hub location being the firstsample area in the scan path and the two or more spokes each comprisingat least two sample areas located along a line, wherein the hub locationis one of the at least two sample areas for each spoke.
 4. The method ofclaim 2, wherein spiral pattern comprises: a home location that is thefirst sample area in the scan path; and at least one consecutive datapoint, wherein the at least one consecutive data point is a sample areathat includes an area of the anatomical cavity that is included by thehome location or one or more of the at least one consecutive datapoints.
 5. The method of claim 1, further comprising supporting featuresexternal to the anatomical cavity.
 6. The method of claim 1, furthercomprising: scanning from an outside portion of the anatomical cavity toan inside portion of the anatomical cavity.
 7. The method of claim 1,wherein the anatomical cavity comprises an ear canal.
 8. The method ofclaim 1, wherein characterizing the anatomical cavity is based on atleast one of: a location of each sample area; an intensity measurementfor each sample area, and a ratio of intensities measured for eachsample area.
 9. An apparatus for scanning an anatomical cavitycomprising: a three-dimensional scanner comprising: a light source thatgenerates light for scanning and identifying locations within theanatomical cavity; a detecting component that receives emitted lightfrom within the anatomical cavity and generates data from the receivedlight; a probe element which guides the light generated by the lightsource; and an inflatable membrane that surrounds the probe element, theinflatable membrane configured to inflate with a medium to a volumeconforming to that of the anatomical cavity; a processor that receivesdata from the detecting component and generates at least distanceinformation; wherein the three-dimensional scanner follows a scan pathwhile scanning the anatomical cavity.
 10. The apparatus of claim 9,wherein the scan path is generated by at least one of thethree-dimensional scanner, at least one processor, and/or a scannersystem.
 11. The apparatus of claim 9, wherein the scan path is basedupon input from a user.
 12. The apparatus of claim 9, wherein the scanpath comprises at least one of a hub and spoke pattern or a spiralpattern.
 13. The apparatus of claim 12, wherein the scan path comprisesa hub and spoke pattern, further wherein a user specifies a hub locationfor the hub and spoke pattern.
 14. The apparatus of claim 12, whereinthe user further specifies the number of spokes in the hub and spokepattern.
 15. The apparatus of claim 13, wherein the processor selectsthe hub and spoke scan path based upon the user specified hub location.16. The apparatus of claim 12, wherein the scan path comprises a spiralpattern, and wherein a user specifies a home location for the spiralpattern.
 17. The apparatus of claim 16, wherein the processor selectsthe spiral scan path based upon the user specified home location.